The mini-sub "Seehund" was the end result of a development of simple weapons of attack by the German navy towards the end of the Second World War. Due to its slim shape, which could not be located by the then sonar, its quiet engine and good seaworthiness, the German navy had great hopes for the operation of this little weapon of war. The 285 built sank 93,000 GRT of enemy shipping and the French destroyer "La Combattante". A single voyage could last up to seven days, which made enormous demands on the physical and mental reserves of the two crew members.